A number of methods of providing dermatological treatments, such as, for example, intense pulsed light based treatments and laser treatments, produce significant levels of pain in patients, leading to the use of anesthetics or analgesics to make patients more comfortable during and immediately following these treatment. Systemic analgesics have been used to reduce pain, but these can lead to unwanted side effects and can be less effective than desired. Topical anesthetics are more commonly used but these can also produce unwanted side effects, including systemic uptake of the anesthetic. Also, as only lower concentrations of topical anesthetics are currently marketed in the United States, physicians often use compounded materials containing higher concentrations of anesthetic. The use of compounded materials presents concerns about product stability, homogeneity and quality in addition to concerns about side effects and systemic uptake.
A number of non-pharmacologic methods of reducing pain have been used for different purposes. For example, transcutaneous electroneurostimulation has been shown to relieve chronic and acute pain (Ersek (1977) Transcutaneous electrical neurostimulation: a new therapeutic modality for controlling pain, Clin Ortop Relat Res. 128:314-24). Applying pressure or pinching skin before and during an injection has been widely reported to reduce the severity of the pain of the injection (Fletcher (2004) Painless Depo-medroxyprogesterone acetate (DMPA) injections using the ‘pinch technique’, J Obstet Gynaecol 24(5):562-3). The use of vibratory stimulation has also been proposed to reduce pain, but results have not been conclusive (Saijo et al. (2005) Lack of pain reduction by a vibrating local anesthetic attachment: a pilot study, Aneth Prog 52(2):62-4). These non-pharmacologic methods require that some sort of physical contact is used to stimulate a response in tissue in order to be effective. However, implementing a method using stimulation based on physical contact with tissue can be problematic when combined with a dermatological treatment which may also require contact with the tissue. For example, the delivery mechanism for the dermatological treatment device can interfere with the stimulation by directly contacting or covering the tissue. If the dermatological treatment device requires the use of a contact plate or window, using the contact plate or window itself to stimulate a response in tissue can be difficult. If the stimulation is based on a touch stimulus, the amount of pressure that needs to be applied to the contact plate or window in order to stimulate the tissue can be more than enough pressure to deform the tissue, which in turn can affect the dermatological treatment. Also, if the stimulation is based on a touch stimulus, it may require that the delivery handpiece is vibrated or is repeatedly put in contact and removed from contact with the tissue while the treatment is delivered, which in turn can affect the dermatological treatment. Further, devices which incorporate a means for stimulating tissue in a delivery handpiece can be substantially more complicated to design, manufacture and maintain.
Thus, a need exists for non-pharmacologic methods of reducing the pain of dermatological treatments by stimulating a touch sensation in a patient which are compatible with the various sorts of dermatological treatment devices on the market and in development. Such non-pharmacologic methods of reducing pain by stimulating a touch sensation can be used alone in order to reduce pain during or immediately following a dermatological treatment, or can be used to supplement other methods of analgesia and/or anesthesia.